docs: def uniprot_sites(uniprot_id):
      """Retrieve a list of UniProt sites parsed from the feature file
  
      Sites are defined here: http://www.uniprot.org/help/site and here: http://www.uniprot.org/help/function_section
  
      Args:
          uniprot_id: Valid UniProt ID
  
      Returns:
  
      """
  
      r = requests.post('http://www.uniprot.org/uniprot/%s.gff' % uniprot_id)
      gff = StringIO(r.content.decode('utf-8'))
  
      feats = list(GFF.parse(gff))
      if len(feats) > 1:
          log.warning('Too many sequences in GFF')
      else:
          return feats[0].features